1. Field of the Invention
The present invention generally relates to management of data capture systems, such as electro-optical readers, preferably laser scanners for reading indicia, such as bar code symbols, as well as imagers for capturing an image of such indicia, as well as radio frequency identification (RFID) devices for identifying targets and, more particularly, to bidirectional communications between a data capture system and a remote host for status and error reporting, upgrading and like management functions.
2. Description of the Related Art
Various electro-optical systems or readers have been developed for reading indicia such as bar code symbols appearing on a label or on a surface of an article. The bar code symbol itself is a coded pattern of graphic indicia comprised of a series of bars of various widths spaced apart from one another to bound spaces of various widths, the bars and spaces having different light reflecting characteristics. The readers function by electro-optically transforming the pattern of the graphic indicia into a time-varying electrical signal, which is digitized and decoded into data relating to the symbol being read.
Typically, a laser beam from a laser is directed along a light path toward a target that includes the bar code symbol on a target surface. A moving-beam scanner operates by repetitively sweeping the laser beam in a scan line or a series of scan lines across the symbol by means of motion of a scanning component, such as the laser itself or a scan mirror disposed in the path of the laser beam. Optics focus the laser beam into a beam spot on the target surface, and the motion of the scanning component sweeps the beam spot across the symbol to trace a scan line across the symbol. Motion of the scanning component is typically effected by an electrical drive motor.
The readers also include a sensor or photodetector which detects light along the scan line that is reflected or scattered from the symbol. The photodetector or sensor is positioned such that it has a field of view which ensures the capture of the reflected or scattered light, and converts the latter into an electrical analog signal.
In retroreflective light collection, a single optical component, e.g., a reciprocally oscillatory mirror, such as described in U.S. Pat. No. 4,816,661 or U.S. Pat. No. 4,409,470, both herein incorporated by reference, sweeps the beam across the target surface and directs the collected light to the sensor. In non-retroreflective light collection, the reflected laser light is not collected by the same optical component used for scanning. Instead, the sensor is independent of the scanning beam, and has a large field of view so that the reflected laser light traces across the sensor.
Electronic control circuitry and software decode the electrical analog signal from the sensor into a digital representation of the data represented by the symbol that has been scanned. For example, the analog electrical signal generated by the photodetector may be converted by a digitizer into a pulse width modulated digitized signal, with the widths corresponding to the physical widths of the bars and spaces. Alternatively, the analog electrical signal may be processed directly by a software decoder. See, for example, U.S. Pat. No. 5,504,318.
The decoding process usually works by applying the digitized signal to a microprocessor running a software algorithm, which attempts to decode the signal. If a symbol is decoded successfully and completely, the decoding terminates, and an indicator of a successful read (such as a green light and/or audible beep) is provided to a user. Otherwise, the microprocessor receives the next scan, and performs another decoding into a binary representation of the data encoded in the symbol, and to the alphanumeric characters so represented. Once a successful read is obtained, the binary data is communicated to a host computer for further processing, for example, information retrieval from a look-up table.
Both one- and two-dimensional symbols can be read by employing moving-beam scanners, as well as solid-state imagers. For example, an image sensor device may be employed which has a one- or two-dimensional array of cells or photosensors which correspond to image elements or pixels in a field of view of the device. Such an image sensor device may include a one- or two-dimensional charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) device and associated circuits for producing electronic signals corresponding to a one- or two-dimensional array of pixel information for a field of view.
It is therefore known to use a solid-state device for capturing a monochrome image of a symbol as, for example, disclosed in U.S. Pat. No. 5,703,349. It is also known to use a solid-state device with multiple buried channels for capturing a full color image of a target as, for example, disclosed in U.S. Pat. No. 4,613,895. It is common to provide a two-dimensional CCD with a 640×480 resolution commonly found in VGA monitors, although other resolution sizes are possible.
It is also known to use radio waves to automatically identify objects, people, or like targets. An RFID tag or transponder identifies a target. An RFID reader interrogates the tag and converts radio waves reflected back from the tag into digital data.
As satisfactory as such moving-beam scanners, imagers and RFID devices are in capturing data, such data capture systems do not have status or error reporting capabilities. When operating problems arise in such systems, much time and effort are required to report the problem, diagnose the problem, and service the problem. It is up to a human user to detect the problem and initiate the process of reporting the failure. This can lead to costly disruptions due to the system being out of service. Servicing generally requires the system to be disassembled for repair. Sometimes, the user has insufficient expertise to recognize the onset of a system problem and delays reporting until a complete system failure has occurred.